Airspy HF+: What you hear, is what you get

It has been dubbed “game changer” and indeed, the Airspy HF+ is a completely other animal of software-defined radio, or SDR. Developed by Youssef Touil plus team and produced by ITEAD, it sells for just US-$ 199 right from factory at Shenzhen, China. This is considered the middle class of SDRs, starting with cheap USB sticks under 10 US-$ and scratching the mark of nearly US-$ 5.000 with Winradio’s WR-G39DDC. This one also marks the transition zone from what even an engaged hobbyist allows himself to spend to the truly professional receivers of e.g. Rohde & Schwarz and Plath. To make it clear: You may achieve professional results at each price tag, even from an RTL & its clones, as Carl Laufer’s excellent blog shows almost daily.

The Serious HF-DXers in mind

Airspy HF+ has been developed with the serious HF (shortwave) listener in mind. In this field it sets new standards regarding sensitivity, dynamic range and noise. Its stunning performance is achieved by a revolutionary approach and a careful layout of the hardware, housed in a sturdy metal case.

I don’t want to add another explanation of this concept (my test report will appear in 1Q/2018 in “Funkamateur“) but just offering the pure stuff. Some first twelve audio examples should give you a truly hands-on impression to answer the one and only question: How loud does this animal roar?
Therefore, I compared about 100 often vastly different situations on HF between Elad’s FDM-S2 (US-$ 525) and Airspy HF+. From this collection, I carefully selected some first twelve examples to cover the needs of the casual listener as well as the hard-core DXer.

Dare to make use of your own understanding

First, you read a description of the case, followed by a recording with FSM-S2 and then by Airspy HF+. Each of both examples has been recorded with exactly the same bandwidth, mode, AGC etc. which had been optimized for that situation. You must listen to these audio clips with headphones to scrutinize the mostly very small differences. Aim you ear towards fading, noise and intelligibility.
This is not a traditional test, where the master of ceremonies masticates the results for you. It’s for the truly demanding DXer, “to make use of your own understanding” (Kant, 1784). Just a hint: weak stations make the difference!

Fasten your Headphones: The Examples

The audio examples are roughly sorted from easy to difficult signals. They were made in the first week of December, 2017.

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6 comments

Hi Nils, Thanks for your careful comparisons. The last two pairs of recordings were the most interesting to me and show what both SDRs can do with very difficult signals. I believe that my forthcoming HF+ units will definitely keep up with the FDM-S2 on DXpeditions!

… thanks, Guy – in the early hours of my test, I even deleted one pair of audio clips because I thought they were just the same … But the deeper you get into the underwood of HF DX, the more visible gets a slight difference, and the + of HF+ … 73 Nils

Hello again Nils, I see you used SDR Console for your HF+ comparison and audio clips. Have you heard any news on availability of an *official* EXTIO.dll file for the HF+? The only one I have heard of is the beta EXTIO software from IW0HDV (Montefusco), and I am not sure it is in a “ready to go” compiled format. I hope an EXTIO will be available by the time my HF+ units arrive. 73…Guy